1. Field of the Invention
The present invention relates to a document modification apparatus and an image processing apparatus equipped with the document modification apparatus, for modifying image data obtained by reading a manuscript such as a document.
2. Description of the Related Art
Conventional document modification apparatuses have performed crosshatching, underlining, and enhancing for characters and photo images in a target document to be modified. There are many types of the document modification apparatuses, which are well known, such as Tablet digitizer type, Coordinate input type, Document region reading type, and so on. Those conventional document modification apparatuses have following drawbacks.
In the tablet digitizer type, an operator specifies an optional region in a document placed on a digitizer by using a pencil, and also designates a modification type for the designated region, and after this, it is necessary for the operator to put the document on the document table again. Accordingly, there is a drawback that this type of the conventional document modification apparatuses causes a shift of a position to be modified.
In the coordinate input type, the coordinate of a target modification region observed from the standard point is predicted by an operator in advance under the state that the document is set on the document table, and it is then necessary for the operator to input this coordinate through an operation section. This introduces a drawback to take more time.
In the document region reading type, it is necessary for an operator to mark directly a region in a document to be modified by using a marker pencil. Accordingly, this type of the conventional document modification apparatuses causes a drawback to stain the document with ink.
In order to eliminate those conventional drawbacks described above, a conventional pre-scan display method has been proposed, in which an image input means reads the document placed on a document table and a display device then displays the image of the document. The operator then specifies a region in the document to be modified while watching the image on the display device. In particularly, there is a region specifying method of extracting a target region from a document and of specifying a modification information for the extract region, that has been disclosed in the Japanese patent document (Japanese laid open publication No. 4-157876). In order to increase the precision of the designation of the modification position, this conventional technique uses a method of designating the region by extracting a binary image region in the original document and an intermediate graduation region and by displaying a distribution relationship of them. This also causes to decrease the operator's work during the designation process for the modification position.
By the way, although the above conventional technique of Japanese laid-open publication No. 4-157876 can handle a document, as a target to be modified, only including characters and photographs, it cannot separate characters and cut characters from a table and a frame in a document, and it further cannot cut cells from a table in a document. Thus, the conventional techniques have drawback to limit the types of the documents as the target to be modified.